malloc和定位new表达式

#include <iostream>
#include <stdlib.h>
using namespace std;

class xiaok{
public:
	int k;
	int a;
	void han(){cout<<k<<a<<endl;}
};
int main(int argc, char const *argv[])
{
	xiaok *p=(xiaok*)malloc(sizeof(xiaok));
	new(p) xiaok();
	p->a=10;
	p->k=20;
	p->han();
return 0;
}

//////////-------------------------
#include <iostream>
#include <stdlib.h>
using namespace std;

class xiaok{
public:
	int k;
	int a;
	void han(){cout<<k<<a<<endl;}
};
int main(int argc, char const *argv[])
{
	void *p=malloc(sizeof(xiaok));
	new(p) xiaok();
	xiaok *vp=(xiaok*)p;
	vp->a=10;
	vp->k=20;
	vp->han();
return 0;
}